<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>留言板</title>
    <style>
        .container {
            width: 350px;
            height: 300px;
            margin: 0 auto;
            /* border: 1px black solid; */
            text-align: center;
        }

        .grey {
            color: grey;
        }

        .container .row {
            width: 350px;
            height: 40px;

            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .container .row input {
            width: 260px;
            height: 30px;
        }

        #submit {
            width: 350px;
            height: 40px;
            background-color: orange;
            color: white;
            border: none;
            margin: 10px;
            border-radius: 5px;
            font-size: 20px;
        }
    </style>
</head>

<body>
    <div class="container">
        <h1>留言板</h1>
        <p class="grey">输入后点击提交, 会将信息显示下方空白处</p>
        <div class="row">
            <span>谁:</span> <input type="text" name="" id="from">
        </div>
        <div class="row">
            <span>对谁:</span> <input type="text" name="" id="to">
        </div>
        <div class="row">
            <span>说什么:</span> <input type="text" name="" id="say">
        </div>
        <!-- onclick="submit()":
        当用户点击这个按钮时，会调用名为 submit 的 JavaScript 函数。
        你需要确保在你的 JavaScript 代码中定义了这个 submit 函数，
        以便在按钮点击时执行相应的操作。 -->
        <input type="button" value="提交" id="submit" onclick="submit()">
        <!-- <div>A 对 B 说: hello</div> -->
    </div>

    <script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.7.1/jquery.min.js"></script>

    <script>
        function submit() {
            //获取三个表框的值
            let from = $("#from").val();
            let to = $("#to").val();
            let say = $("#say").val();

            //进行判断
            if (from == "" || to == "" || say == "") {
                return;
            }
            //不为空的情况
            let message = "<div>" + from + "对" + to + "说：" + say + "</div>";
            $(".container").append(message);

            //清空数据信息
            $("#from").val("");
            $("#to").val("");
            $("#say").val("");
        }
    </script>


</body>

</html>